Computing devices, such as personal computers, tablet computers, mobile phones, or other devices, often request content from other computing devices over a network. In a common application, the computing device operated by a requesting user is referred to as the client, and the computing device or system operated by the content provider that responds to the request is the server. A client and server may communicate over an intranet, the Internet, or any other communication network. Clients receive and process content (e.g., web pages) from content servers, either directly or through intermediary systems, such as proxy servers.
Various services exists for measuring the popularity levels of particular web sites, web pages, search terms, and topics. These services rely on various sources of behavioral data, such as search engine traffic, blog posts, and Twitter posts, to gauge the popularity of particular topics and content items. While such services are useful, they frequently do not provide a sufficiently reliable, useful, and timely indication of the topics and content items that currently gaining in popularity.